PROJECT SUMMARY Delivering effective tobacco dependence treatment that is feasible within low dose spiral CT (LDCT) clinics is crucial for realizing the health benefits of lung cancer screening. The Centers for Medicare and Medicaid Services requires that LDCT shared decision making with smokers include ?counseling on the importance of smoking cessation and furnishing of information about tobacco cessation interventions.? This approach is analogous to the Ask-Advise-Refer (AAR) model in which providers Ask about smoking status, Advise a smoker to quit, and Refer to cessation resources. To date, passive referral to treatment has failed to increase treatment use. Proactively connecting smokers to treatment can increase treatment use. Emerging evidence supports the effectiveness and cost efficiency of proactively linking smokers to digital cessation treatment through the electronic health record (EHR). Digital interventions (i.e., web-based and text message) are effective, sustainable, scalable, and cost efficient. Use of digital technologies is common among older adults and continues to increase steadily as the sizable population of digitally-connected middle aged adults ages. This study will evaluate the impact of a proactive, EHR-supported enrollment strategy that links LDCT-eligible smokers with an evidence-based intervention comprised of a web-based program and integrated text messaging. The scalability and sustainability of a digital intervention may represent the most cost effective and feasible approach for LDCT clinics to proactively engage large numbers of smokers in modestly effective cessation treatment. However, given that patients seen in LDCT clinics will be older, established heavy smokers with varying levels of interest in quitting, we will also evaluate the impact and cost effectiveness of adding proven clinical intervention provided by a tobacco treatment specialist. We expect that a combined digital/clinical intervention will yield higher quit rates than digital alone, but that it may not be as cost effective or feasible for LDCT clinics to implement. Our goal is to provide actionable findings about how to most effectively and cost efficiently promote abstinence in LDCT clinics. Using a 3-arm randomized trial design with repeated measures at 1, 3, 6, and 12 months, we will randomize N=1650 smokers who present for LDCT lung cancer screening to an passive referral usual care control condition, proactive referral to a digital cessation intervention that combines web and text messaging, or proactive referral to a digital cessation intervention combined with Tobacco Treatment Specialist counseling. We will examine overall effectiveness of the interventions in promoting abstinence, the impact of proactive referral to treatment, and the total cost and cost effectiveness of the interventions. We will also examine the representativeness of the enrolled sample and explore barriers and facilitators to intervention adoption with LDCT clinic leaders. Our trial is structured as a practical clinical trial to answer key questions of direct relevance to LDCT decision-makers. The study is innovative in its use of interoperable, digital technologies to deliver a sustainable, scalable, high impact cessation intervention and to facilitate its integration within clinical practice. This study will add to the growing knowledge base about the overall effectiveness of digital interventions and their role in the healthcare delivery system.